Measuring Voltage with Multimeters – All About Voltage Testing

Ever you need to check the voltage of some outlet supply or volts level coming to electric devices? In that case, you must need a good multimeter that can tell the exact voltage level. To check voltage through a multimeter you don’t need to be an electrician or a trained person first. Just a little knowledge about electrical basics and safety measures are enough for this purpose.

In this guide, we’ll tell you how to check volts through a multimeter in an easy way so that if you need to do it at home or for rv, boats, golf carts, offices for electric appliances you could do it well. Voltage is included in three basic parameters of all multimeters which are volts, ohm and current. For static use, you can also use a panel mount voltmeter which displays realtime voltage readings. Otherwise, a multimeter is the best choice to do it.

Voltage systems in different regions of world

There are basically two types of multimeters, one is analog and the other is digital multimeter. Usually analog one is a professional’s choice. People with no electrical background or know how might get confused in using analog multimeters. So we recommend, if you are a general user or DIY enthusiast you should have an accurate digital multimeter to do minor tasks.

Checking Multimeter Before test

A multimeter should be in fit condition before you want to use it for any test. Just take a look at your multimeter condition, parts if they are well? Meter should not be damaged from any side, also the leads should be intact and in working condition. A general test can tell lead condition, you can do it before every test to verify leads and meter working. Set multimeter to resistance mode and connect both tests leads to one another if the multimeter is giving a beep sound and result in less than 0.5 ohms that mean the device is in good condition.

How to Measure Ac Voltage with a Multimeter

Most of the appliances we used at home run at ac voltage supply. Others that are designed to work on dc come with ac to dc adaptor which supplies them with their required dc voltage. Also at the industry level, all machinery runs on ac power whether single phase I.e 120, 220v or three phase 440v. Checking ac voltage with a multimeter is a quite simple process that can be done easily with some basic safety precautions. We conclude it by some simple steps which are given below,

  1. First of all insert black testing lead to COM socket and red lead to VΩ socket, it’s properly marked across related sockets.
  2. Now set range if you have a manual range multimeter. Firstly, you should set range to maximum level if you don’t know circuit’s voltage.
  3. You can see separate ranges for both ac and dc voltage in manual range meters, carefully set range according to voltage type you are going to test.
  4. In auto range multimeters there’s no need to set range first.
  5. Now connect meter leads to circuit points, in single phase systems connect red lead to phase and other lead to neutral. In three phase you can check voltage by connecting both probes to any of two phases of three in any order.
  6. Repeat the process if necessary.
  7. Remove test leads when finished with your test.

How to Measure Dc Voltage with a Multimeter

In a modern world where technology is improving day by day optimization of electric appliances’ power becomes more important. Dc power is a type of energy where we achieve big targets by a small amount of energy consumed. Like for industrial automation, gadgets, battery operated items, and offshore appliances dc supply is a vital power source.

Procedure of checking dc voltage is not much different than of ac voltage with some minor changes. Usually, we have to check dc voltage of magnitudes 6v,9v,12v and 24v. Step by step process is given below,

  1. First you have to adjust leads into volts measuring socket and COM socket accordingly.
  2. Now is the time to set range through rotary wheel selector switch of multimeter. In manual range meters there is separate range for dc volts.
  3. Set range according to magnitude of voltage being measured.
  4. If you want to measure dc millivolts, select mv from range options.
  5. Now connect probes to circuit or device from where you want to measure dc volts.
  6. Check readings on display.
  7. You can also press hold button to freeze reading, min/max to check minimum and maximum readings of circuit provided in some modern multimeters.

How to Check 240 Voltage with a Multimeter

In many countries, single phase voltage supply is 240 or 220 volts, while in usa and others we get 120 volt systems. 220 and 120 v both are single phase or general household supply systems. This magnitude voltage can be checked even by some cheap or low budget multimeters accurately.

If you are testing 240v with manual range multimeters you have to set the range at 240v ac which is illustrated by ac sinewave. Now repeat the same process which is mentioned above for voltage measurements. Just remember one thing that black probe is for neutral and red has to be connected with phase because in ac voltage supplies phase and neutral are opposite ends of flowing power.

How to Measure Voltage in a Circuit

It depends on the nature and complexity of that particular circuit. A circuit is maybe a simple electric motor, inverter, and plc system of complex industrial automation systems. What’s your goal whether you want to test the complete voltage supply to the circuit or have to check some certain part’s supply of that circuit. You can start from initial point of the circuit if the supply is ok then check the ending point voltage.

Sometimes in troubleshooting we have to test a malfunctioning part of a circuit for this we can test it by connecting test leads to that point and neutral and so on. That’s how we can check if all points have equal voltage supply or not.

Conclusion

Concluding this guide we can say now that using multimeters to find voltage is not more a difficult task now. The only requirements are a careful attitude and safety precautions and you can do it anywhere at any time. Also focus on the range selection process because a wrong range for a test can lead to multimeter’s burning or even a serious injury or shock to you. So you should always double check settings.

We also recommend you to take physical guidance from a trained electrician.

Leave a Comment